1. Field of the Invention
The present invention relates in general to devices for applying dry particulate material. In particular, the present invention relates to an improved device for pneumatic application of dry particulates for agricultural purposes.
2. Description of the Related Art
It has been known for many years to distribute liquid material, especially liquid chemicals or fertilizer for agricultural use by the use of a powered vehicle. The vehicle will carry a large tank adapted to hold a quantity of the liquid. A pump is connected to the tank such that the liquid may be drawn from the tank and pressurized by the pump. The output of the pump is directed through lines to a plurality of nozzle units which ultimately distribute the liquid. To increase the area upon which the liquid is distributed, it has been known to provide booms which extend laterally from the vehicle, and to mount the nozzle units at laterally spaced positions along the booms.
In recent years it has been known to distribute dry particulate material in a similar manner. In particular, it has been known to provide a vehicle having a large storage tank or hopper adapted to receive a quantity of the dry particulate material. A feeding and metering means is associated with the hopper draws the material from the hopper and introduces it into a plenum chamber where the material is entrained within a fluid air stream. The entrained fluid is directed into a plurality of discharge pipes which extend laterally of the vehicle. The discharge pipes have lengths which are staggered in the lateral direction, such that the particulate material exits from the distribution pipes at similar spaced locations to increase the area of distribution. Exemplary pneumatic distribution systems are shown in U.S. Pat. No. 4,793,742 to Strand and U.S. Pat. No. 5,052,627 to Balmer.
While each of these arrangements has proved serviceable, the purchase price of such units is quite high. As may be envisioned, a chemical/fertilizer distributor who wishes to provide his customers with the choice of liquid or dry particulate materials must purchase both types of distribution equipment. Additionally, where both liquid and dry particulate materials are to be distributed within a short period of time, the distributor must send out both a liquid distribution unit and particulate distribution unit, with a driver for each unit, and possibly a supply or nurse truck for each unit. This greatly increases the labor costs associated with distribution of chemicals or fertilizers.
To overcome these drawbacks, it has been known to provide a distribution vehicle which includes a tank for holding liquid material and a separate hopper for holding dry particulate material. The remainder of the distribution systems are similar to those described above, with the pneumatic distribution pipes extending laterally of the vehicle and the nozzle units being located at laterally spaced positions along the distribution pipes.